the only cost you incurred was for IC's to replace them. how much? if the amount was not significant I would just expense them as repairs. if it was a large amount they may still qualify for expensing under the de - minimus rules (under $2,500). they are considered part of the real property, permanently attached so the life would be 27.5 for residential 39 years for commercial property if they don't qualify for expensing
